refactor: the hub is neshub everywhere

Six comments across nescope, neswire and nescapture still named
nestri-guest-hub, plus one still naming nestri-protocol. Deferred from the
import commits so the rename would read as one change rather than six
unexplained edits inside otherwise-verbatim trees.

Comments only. Realigned an ASCII box in encode.rs that the shorter name
knocked crooked.

apps/nescope/src/main.rs

@@ -337,7 +337,7 @@ fn main() {
     }
 
     // ── Input IPC source ─────────────────────────────────────────────────
-    // Connect to the nestri-guest-hub input socket and feed events into the
+    // Connect to the neshub input socket and feed events into the
     // compositor seat. Reconnection is handled in the idle callback.
     let ipc_path = args.input_ipc.clone();
     match input_ipc::InputIpcSource::connect(&ipc_path) {